pk: Move s-expr creation for sign and encrypt to the modules.

* cipher/pubkey.c (pubkey_encrypt): Fold into gcry_pk_encrypt.
(pubkey_decrypt): Fold into gcry_pk_decrypt.
(pubkey_sign): Fold into gcry_pk_sign.
(pubkey_verify): Fold into gcry_pk_verify.
(octet_string_from_mpi): Make it a wrapper and factor code out to ...
* mpi/mpicoder.c (_gcry_mpi_to_octet_string): New function.

* src/cipher.h (PUBKEY_FLAG_FIXEDLEN): New.
* cipher/pubkey.c (sexp_data_to_mpi): Set flag for some encodings.
(gcry_pk_encrypt): Simply by moving the s-expr generation to the modules.
(gcry_pk_sign): Ditto.
* cipher/dsa.c (dsa_sign): Create s-expr.
* cipher/elgamal.c (elg_encrypt, elg_sign): Ditto.
* cipher/rsa.c (rsa_encrypt, rsa_sign): Ditto.
* cipher/ecc.c (ecc_sign, ecc_encrypt_raw): Ditto.
(ecdsa_names): Add "eddsa".
* tests/t-ed25519.c (one_test): Expect "eddsa" token.

Signed-off-by: Werner Koch <wk@gnupg.org>

1 files changed, 58 insertions, 0 deletions

diff --git a/mpi/mpicoder.c b/mpi/mpicoder.c
index 07e91c63..1d2c87e0 100644
--- a/mpi/mpicoder.c
+++ b/mpi/mpicoder.c
@@ -836,3 +836,61 @@ gcry_mpi_aprint (enum gcry_mpi_format format,
     *nwritten = n;
   return rc;
 }
+
+
+/* Turn VALUE into an octet string and store it in an allocated buffer
+   at R_FRAME or - if R_RAME is NULL - copy it into the caller
+   provided buffer SPACE; either SPACE or R_FRAME may be used.  If
+   SPACE if not NULL, the caller must provide a buffer of at least
+   NBYTES.  If the resulting octet string is shorter than NBYTES pad
+   it to the left with zeroes.  If VALUE does not fit into NBYTES
+   return an error code.  */
+gpg_err_code_t
+_gcry_mpi_to_octet_string (unsigned char **r_frame, void *space,
+                           gcry_mpi_t value, size_t nbytes)
+{
+  gpg_err_code_t rc;
+  size_t nframe, noff, n;
+  unsigned char *frame;
+
+  if (!r_frame == !space)
+    return GPG_ERR_INV_ARG;  /* Only one may be used.  */
+
+  if (r_frame)
+    *r_frame = NULL;
+
+  rc = gcry_err_code (gcry_mpi_print (GCRYMPI_FMT_USG,
+                                      NULL, 0, &nframe, value));
+  if (rc)
+    return rc;
+  if (nframe > nbytes)
+    return GPG_ERR_TOO_LARGE; /* Value too long to fit into NBYTES.  */
+
+  noff = (nframe < nbytes)? nbytes - nframe : 0;
+  n = nframe + noff;
+  if (space)
+    frame = space;
+  else
+    {
+      frame = mpi_is_secure (value)? gcry_malloc_secure (n) : gcry_malloc (n);
+      if (!frame)
+        {
+          rc = gpg_err_code_from_syserror ();
+          return rc;
+        }
+    }
+  if (noff)
+    memset (frame, 0, noff);
+  nframe += noff;
+  rc = gcry_err_code (gcry_mpi_print (GCRYMPI_FMT_USG,
+                                      frame+noff, nframe-noff, NULL, value));
+  if (rc)
+    {
+      gcry_free (frame);
+      return rc;
+    }
+
+  if (r_frame)
+    *r_frame = frame;
+  return 0;
+}